Split VLAN 1 Server/DHCP

[Vellocet]

Hi all

 

Wanted some advice on proposed network setup

 

We have 1 domain server which is also dns and dhcp

 

The network is a split range vlan

 

Any problems in setting dhcp to have 2 scopes (server has 2 nics) for each side of the vlan, how would I need to set up dns for clients to resolve the correct ip to the server name?

 

Thanks

[Jamo]

When you say split VLAN, what do you mean?

[twin--turbo]

1 Nic on subnet 1

1 Nic on subnet 2

 

2 scopes, one for each subnet.

 

2 sets of scope options to specify the default route and dns servers.

 

Rob

[Vellocet]

When you say split VLAN, what do you mean?

 

Sorry meant split range on same subnet, the lower part of the range is vlan 1 the upper range is on vlan 2

[IrritableTech]

I think the short answer is, yes, it should work.

 

So if your first nic is assigned 192.168.0.1 and receives a DHCP request, your DHCP server will allocate one on the range 192.168.0.0/25 and if the second nic is assigned 192.168.0.129 the server will allocate an IP in the 192.168.0.128/25 range. DHCP uses the request info (which network it came from) to help assign an IP. We use the same principle to assign IPs across our VLANs, although we use a router, rather than multiple NICs.

[Vellocet]

Cheers, got a few on the test ok and dhcp dishes out correct ips

 

However it seems intermitant what ip address the client thinks is the server, sometimes it pings server name by the correct ip sometimes its looking for the server on the wrong vlan ip

 

Changing the host file sorts it but theres a dns issue somewhere, both ips of the server on in the a records list pointing to the correct server name

[pleach85]

If you are running anything other than a Class C subnet (255.255.255.0) you may need to configure your DNS server with the correct mask used in your network. There's a great blog here DNS and Subnet Priortization & DNS Round Robin - AD and Exchange Quantum Singularity explaining how dns decides what address to return. Essentialy though what you need to do is run the cmd Dnscmd /Config /LocalNetPriorityNetMask 0x000000FF where the hex part is the hex indicates the number of hosts bits (there is a list on the website).

[twin--turbo]

I think the short answer is, yes, it should work.

 

So if your first nic is assigned 192.168.0.1 and receives a DHCP request, your DHCP server will allocate one on the range 192.168.0.0/25 and if the second nic is assigned 192.168.0.129 the server will allocate an IP in the 192.168.0.128/25 range. DHCP uses the request info (which network it came from) to help assign an IP. We use the same principle to assign IPs across our VLANs, although we use a router, rather than multiple NICs.

 

That's two different subnets though, where he says split scope on one subnet.

 

Split scope would be done by two DHCP servers sharing the load of one subnet.

 

Rob

[IrritableTech]

That's two different subnets though, where he says split scope on one subnet.

 

Split scope would be done by two DHCP servers sharing the load of one subnet.

 

Rob

 

Well if that's the case I've misread the original post completely but @Vellocet seemed to suggest it works and now just has a DNS issue?